Silver halide developer containing 2(beta-hydroxyethyl) aminophenol and p-hydroxyphenylamino acetic acid



Patented ept. 9, 1 952 SILVER HALID E DEVELOPER CONTAINING 2 (fi-HYDROXYETHYL) AMINOPHENOL AND p-HYDROXYPHENYLAMINO ACETIG ACID David Hugh Oakley John, Hornchurch, and George Terence James Field, London, England, assignors to May & Baker Limited, Dagenham, England, a British company N Drawing. Application May 12, 1950, Serial No. 161,734.. In Great Britain July 31, 1948 This invention relates to photographic developers and particularly to fine grain photographic developers. a

In British Patent No. 295,939, 2([3-hydroxyethyl) aminophenol is suggested as a photographic developer and developer formulae have been produced based on the use of this compound which give fine grain results .A suitable formula using this compound is as follows:

DEVELOPER A 1 Grams zqi-hydroxyethyl) aminophenol sulphate 6 Sodium sulphite anhydrous 100 Sodium carbonate anhydrous 11.5 Sodium hexametaphosphate 1.7 Potassium bromide 0.6

Water to make 1 litre.

The developer so constituted gives a very fine grain but it has the disadvantage that it develops rather slowly. There is set out below a comparison between this developer and other standard developers in which this point is brought out:

In this table the terms have the following meanings:

Emulsion speed.--Developer C is taken as giving a speed of 100 and all other speed data are expressed as a percentage of this maximum. The speed estimation is based on the determination of the inertia point and a developer giving a speed of 50 would therefore demand twice the initial exposure to five the result of Developer C.

Granularzty inde.r.The granularity given by Developer 13 is assigned the index 100. All other granularities have been expressed relative to this, the lower the figure the less pronounced is the gram.

Fog ZeueZ.-This term has its usual significance in thisfield, being the density of the silver image obtained in the area which has not been exposed to light.

Development time.This is the time required in minutes to give a gamma of 1.6, development being effected at 68 F.

1 The standard developers with which the 9 Claims. (Cl. 95-88) 2 (,B-hydroxyethyl) aminophenol developer is compared have the following formulae:

DEVELOPER B Grams p-Phenylene diamine base 10 Sodium sulphite anhydrous Water to make 1 litre.

DEVELOPER C j p Gram p-Methylaminophenolsulphate 2 Sodium sulphite anhydrous Hydroquinone 5 Borax 2 Water to make 1 litre.

DEVELOPER D p I Grams p-Methyiaminophenolsulphate 2 Sodium sulphite anhydrous 75 Sodium carbonate anhydrous 37 Hydroquinone 8 Potassium bromide 2.

Water to make 1 litre.

It will be seen from the foregoing comparison that the 2(p-hydroxyethyl) aminophenol developer compares very favourably as a fine grain developer, that is to say it gives an emulsion speed closely comparable with those of Developers C and D and yet whereas the granularity indexes of these latter developers are and 2l0respec tively the granularity index of the 2(fi-hydroxyethylaminophenol developer is only 110. The fog level obtained with zqi-hydroxyethybaminophenol developer is low and the main criticism of it is that its development time (18 minutes), while much better than Developer B, is nevertheless long compared with that of Developer C.

It is an object of this invention to provide new developer compositions. yielding fine grain developer images with much reduced development time. It is 'a further object of'this invention to provide concentrated develop-er compositions of such a character which merely require dilution with water for use. It is astill further object of this invention to provide suchde veloper com-' positions in the form of dry powders merely r'e quiring dissolution in water to produce developing solutions. A further object is to provide methods of developing photographic silver halide emulsions whereby fine grain fully developed images may be obtained in a'sho'rt developing time. i

It has now been discovered'that the inclusion in a developer based on 2(fi-hydroxyethyl) aminophenol (usually employed as the sulphate) of a quantity of p-hydroxyphenylamino acetic acid, i. e. photographic glycine, reduces very considerably the development time. without having any appreciable effect onany of its other characteristics.

According to the present invention, therefore,

a photographic developer for silver halide emulv sions comprises 2(fl-hydroxyethyl)aminophenol and p-hydroxyphenylamino: acetic; acid; and:

more particularly according to the invention'the developer comprises these two compounds in" aqueous alkaline solution .andaparticularly in: association with alkali su1phites,. e; g. sodium bonate, and other compoundscommon to photosulphite, alkali carbonates, e. g. sodium cargraphic developers. Such other compoundssmaybe, for example, borax, sodium metaborate, trisodium phosphate and sodium heXametaphos-- Example Grams 2(B-hydroxyethyl) aminophenol sulphate; 6- p-Hydroxyphenylamino acetic acid 1.13 Sodium sulphite anhydrous- 100 Sodium carbonate anhydrous 11.5 Sodium hexametaphosphate 1.7 Water to make 1 litre.

This developer was compared with Developer A andalso-with Developer'A'modified" by the omission of 1 the potassium bromide-,- and gave the following results:

From .-.theseresults it is clearthat the :emulsion: speed .and granularity index given by the three developers is substantially identical. The foglevel increase shown bythelast-two develop ers isnotseriousinpractice; Onthe'other hand whereas. a small decrease in development time can.- be achieved- .by-omittingl the potassium bromide fromlDevelopersA, the effect -ofincluding p-lhydroxyphenylaminoacetic acid -is to reduce the :development rtime byamore than half. a

The invention includes the new developers in the form vof solutions (readyforuse, or highly concentrated) andalso-in-the form zofl-dry-packed powders.

We claim: 1

l. A photographicdeveloper for" silver halide emulsions which co'mprises'a salt of '2 (fi-hydroxyethyllaminophenol, p-hydroxyphenylamino-ace tic acid and an alkali carbonate in aqueous-solution the concentration: of 2((3-hydroxyethyl)- aminophenol-(calculated-as sulphate) being :be-

tween 4 and 8 grams per litre, and the concentration of p-hydroxyphenylamino acetic acid being from 10-30% of the said concentration of 2 (B-hydroxyethyl) aminophenol.

2. A photographic developer for silver halide emulsions which comprises a salt of 2 (ll-hydroxyethyl)aminophenol, p-hydroxyphenylamino acetio acid, an alkali carbonate and an alkali sulphite-inaqueous solution the concentration of 2([3-hydroxyethyl) aminophenol (calculated as sulphate) being'between 4 and 8 grams per litre, and 'the concentration of p-hydroxyphenylamino aeetic-acid'beingirom lO-30% of the said concentration of '2-(fl-hydroxyethyl) aminophenol.

3.'A photographic developer for silver halide emulsions whichv comprises a salt of 2(fi-hydroxyethyl) aminophenol, p-hydroxyphenylamino acetic acid, an alkali carbonate, an alkali sulphite and sodium hexametaphosphate in aqueous solution the concentration of 2(B-hydroxyethyl)- aminophenol- (calculated assulphate) beingbebetween l-and .8'grams per litre; andthe concen tration of p-hydroxyphenylamino aceticacidbe-- ing, from -10-30%' of the.saidiconcentrationof 2 (B-bydroxyethyl) aminophenol;

4-; A photographic 'developerfor :silverhalide emulsions comprising .a saltof." 2(fl-hydroxyethyl) aminophenol and pehydroxyphenylamino acetic acid in aqueous alkaline-solution, the concentration of 2(5 hydroxyethyDaminophenol (calculated as sulphate) being between 4 and 8 grams per litre, and the concentration of p-hydroxyphenylamino acetic acid being from ill-30% of a the said concentration of 2 (,B-hydroxyethyb aminophenolr 5. A photographic developersfor silver halideemulsions containing the following-ingredients in substantially the followingproportions:

. Grams 2(p hydroxyethyl)aminophenoll su1phate 6- peI-IydroXyphenylamino acetic acid Sodium sulphite anhydrous Sodium carbonate anhydrous 11.5 Sodium hexametaphosphate 1.7 Water to make 1 litre.

6. A dry photographic developer composition for silver halide emulsions comprising a'salt of 2 (c-hydroxyethyl) aminophenol, p-hydroxyphenylamino acetic-acid andan alkali the proportion of p-hydroxyphenylamino acetic acid being 10-30% by weight of the said salt.

'7. A dry photographic developer composition for silver halide emulsions comprising a .salt of 2 (pi-hydroxyethyl) aminophenol, p-hydroxyphenylamino acetic acid, an. alkali sulphite and an alkali carbonate theproportion of p-hydro-xyphenylarnino acetic acid being- 10-30%by weight of the said salt.

8. Process forthedevelopment of a photographic SilVBI'nhELHdG emulsion which comprises subjecting an exposed'" photographic element carrying a layer of'such emulsion to" treatment with .adeveloper comprising 'a--sa1t-ofi 2( B-hydroxyethy-l)aminophenol and p-hydroxyphenylamino acetic acid in aqueous alkaline solution the concentration of 2(,8-hydr'oxyethyl) aminophenol (calculated "as" csulphate). being between 4 and vii-gramspervlitre, and the concentration of p-hyclroxyphenylamino acetic acid beingzirbm' 10-30% of the said a concentration .of :21(-,3 -hydroxyethyl)aminophenol.

9. Process for the development lofeaphotoraphic silver- "halide: emulsion which :"com

2,610,122 5 c v be subjecting an exposed photographic element REFERENCES CITED carrying layer of Such emulsion to treatment The following references are of record in the with a developer comprising a salt of 2(p-hyfile of this patent: droxyethyl) aminophenol, p-hydroxyphenylamino acetic acid, an alkali carbonate and. an alkali 5 UNITED STATES PATENTS sulphite in aqueous solution the concentration of Number Name Date 2(fi-hydroxyethyl)aminophenol (calculated as 1,758,762 Reddelien May 13, 1930 sulphate) being between 4 and 8 grams per litre,

and the concentration of p-hydroxyphenylamino OTHER REFERENCES acetic acid being from 10-30% of the said con- 10 Henney & y: Handbook of ecentration of 2(p3-hydroxyethyl)aminophenol. y McGraw-Hill. W York, 1939, P

DAVID HUGH OAKLEY JOHN. GEORGE TERENCE JAMES FIELD. 

4. A PHOTOGRAPHIC DEVELOPER FOR SILVER HALIDE EMULSIONS COMPRISING A SALT OF 2(B-HYDROXYETHYL) AMINOPHENOL AND P-HYDROXYPHENYLAMINO ACETIC ACID IN AQUEOUS ALKALINE SOLUTION, THE CONCENTRATION OF 2(B - HYDROXYETHYL)AMINOPHENOL (CALCULATED AS SULPHATE) BEING BETWEEN 4 AND 8 GRAMS PER LITRE, AND THE CONCENTRATION OF P-HYDROXYPHENYLAMINO ACETIC ACID BEING FROM 10-30% OF THE SAID CONCENTRATION OF 4(B-HYDROXYETHYL)AMINOPHENOL. 